Indoor positioning services have been widely used in various fields such as navigation,rescue and disaster relief.Indoor positioning methods based on Bluetooth sensors can be realized by some built-in functions of mobile phones,so they are easy to popularize and practical,but they often perform poorly in crowded areas and complex electromagnetic environments.To address this issue,a fingerprint indoor positioning method fusing Bluetooth and geomagnetism is proposed.Firstly,a number of Bluetooth beacons are set up in the shopping mall to be positioned,and the iBeacon function and Hall sensor of mobile phones are utilized to receive Bluetooth and geomagnetic signals respectively.Then,the Bluetooth estimated coordinates and the geomagnetism estimated coordinates are fused at the decision-making level to calculate the user position,which not only reduces the positioning error but also avoids the additional hardware resource consumption.The experimental results show that the proposed method significantly improves positioning accuracy.
Aiming at the problem that the existing network security mechanism focuses on addressing the credibility of user identity, whilst not solving the credibility of user behavior, This paper proposes a credibility evaluation model based on multi-dimensional decision attributes of user behavior. The model quantifies the credibility of user behavior from multiple decision attributes (e.g., direct credibility, indirect credibility, behavior activity considering behavior incentive factors), and uses entropy weight method to determine the weight of each decision attribute. Then the hierarchical space of user behavior credibility evaluation is established adaptively. Finally, this paper employs the mapping mechanism between user credibility level and service level, in order to realize the trusted management of user behavior.
针对网络攻击出现的大规模、协同、多阶段的特点,提出一种基于攻击图模型的网络安全态势评估方法.首先,结合攻击事件的时空特征融合多源告警数据构建网络攻击行为特征;其次,基于告警信息映射攻击节点,关联多步攻击的路径;再次,在构建攻击图的基础上,结合转移序列构建攻击节点转移概率表,将转移概率引入攻击图中,推断攻击者的攻击意图;最后,针对最大可能的攻击路径,对大概率的攻击节点进行安全态势评估,科学量化网络攻击后潜在攻击节点的安全态势,为网络安全管理人员提前做好防护提供理论支撑和科学依据.
